1. Field of the Disclosure
The present disclosure relates to x-ray machines, and more particularly, to retrofitting an existing x-ray system having an x-ray generator with a retrofit device, where the retrofit device resets a digital receiver panel in preparation for illumination by an x-ray exposure from the x-ray generator. The retrofit device provides for detecting an x-ray preparation signal so that the digital x-ray detector may be initialized to receive the x-ray exposure. The retrofit device is compatible with a variety of x-ray preparation signal characteristics and does not alter a preexisting x-ray preparation signal, thereby removing the need to modify existing equipment, and preserving the existing equipment's original functional characteristics. The retrofit device also includes provisions for conditioning the received x-ray preparation signal, before transmitting a further control signal to the digital x-ray detector, to enhance compatibility with various x-ray generators.
2. Description of the Related Art
Digital radiography systems capture radiation of an x-ray exposure on photo-sensitive layers of a digital x-ray receiver panel. The photo-sensitive layers, when read by a computer, provide an image of an internal structure of an exposed area, i.e., a digital x-ray image, on a digital screen, e.g., a computer screen. The digital x-ray image is stored in a database for subsequent access. In addition, the digitally rendered x-ray picture can be transmitted to remote locations for analysis and diagnosis from a radiologist.
Digital radiography provides desirable benefits over conventional systems that utilize film or cassette technologies. However, with digital radiography, a digital x-ray receiver panel must be reset prior to an x-ray exposure. This reset alleviates unwanted noise from the photo-sensitive layers of the digital x-ray receiver panel and mitigates against additional exposures due to noisy, or inaccurate, x-ray images.
Many types of digital x-ray detectors require synchronization with each x-ray exposure. These detectors must receive a signal in advance, so they can become ready to capture an x-ray. Some of these detectors also depend on the signal to remain active throughout the entire duration of the x-ray exposure, while other detectors will automatically stop capturing after a predetermined time (e.g., length of maximum-duration exposure). To ensure both patient safety and proper image quality, the detector must receive the signal a minimum amount of time before the possibility of x-ray exposure, to ensure that no x-ray radiation is produced while the detector is not ready to receive it.
Most full-size x-ray generators support signal integration intended for reciprocating buckys, typically referred to as a Bucky Interface, which already conforms to the synchronization requirements of such digital x-ray detectors. However in the realm of mobile x-ray imaging, where x-ray generators are downsized and reciprocating buckys are considered too bulky for their possible benefits, x-ray generator manufacturers have left out support for such signal integration.
The fact that the digital x-ray detector consumes electrical power through its initialization input means that it could prevent the x-ray generator from recognizing the preparation signal, if routed directly through the detector's input. As well, the fact that the digital x-ray detector's initialization input may require specific electrical characteristics (e.g. voltage, timing) that are different from the x-ray generator's preparation signal means the signal may not be compatible, if routed directly.
Therefore, to retrofit a digital x-ray detector requiring synchronization to an x-ray generator that does not support sending signals to such an external device, a creative approach is necessary. An ideal solution is one that does not require operational or constructional modifications to the x-ray generator or digital x-ray detector, yet where all x-ray radiation produced during an exposure event contributes to developing a digital x-ray image.
U.S. Pat. No. 7,844,031 to Newman et al. is directed to an apparatus that adapts a preexisting system that includes a conventional film-based and/or computed radiography x-ray imaging system, for use with a retrofit digital radiography detector. The apparatus includes an interface and control circuit that interfaces with the digital radiography detector and an x-ray generator. However, the interface and control circuit must either be installed between a preexisting operator controller and the x-ray generator, or replace the preexisting operator controller. Thus, the use of the apparatus requires a modification of the preexisting system and possibly alters electrical characteristics of signals that would ordinarily be transmitted from the preexisting operator controller to the x-ray generator.